(a) Field of the Invention
The present invention relates to an electrode for vapor deposition process and a manufacturing method thereof. More particularly, the present invention relates to an electrode for vapor deposition process that is used to vapor-deposit polysilicon for manufacturing a solar cell and a manufacturing method thereof.
(b) Description of the Related Art
Solar cells are divided into crystalline type and thin film type depending on raw material and technology. Generally, manufacturing cost of solar cells of crystalline type is higher than that of solar cells of thin film type, but the solar cells of crystalline type has higher photovoltaic property than the solar cells of thin film type. Therefore, the solar cells of crystalline type make up majority of the solar cell market. The solar cells of crystalline type use polysilicon as raw material.
Siemens Method is well known as a manufacturing method of the polysilicon. As shown in FIG. 1, a silicon filament is disposed in a reactor and is heated by electricity, and TCS gas is supplied to the reactor according to the Siemens Method. If MG-Si (95-99.5% purity) obtained by removing O2 and impurities from silicon that exists as SiO2 in nature is reacted with HCL, various gases containing TCS are generated. After that, TCS gas is separated through distillation from the various gases.
If TCS gas is supplied into the reactor, silicon molecules is deposited on a surface of the silicon filament heated to high temperature. Through these processes, silicon filament becomes thicker and is developed to a silicon rod.
If the silicon rod is broken into a suitable size, bulk polysilicon that can be used for manufacturing the solar cell is finally obtained.
When manufacturing the polysilicon, at least one electrode is mounted at a lower portion of the silicon filament so as to apply electricity in the reactor. Such an electrode endures high temperature environment so as to maintain electrically conducting state. Since the electrode is manufactured by cutting a pillar to have a predetermined shape and digging the pillar so as to form a coolant passage according to conventional arts, mass production may not be suitable and manufacturing cost may increase due to increasing use of raw material.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.